What is an overripe cherry in coffee harvesting?

An overripe cherry is a coffee cherry that has remained on the tree past its peak ripeness. Overripe cherries are soft, darker than ripe fruit, and often begin to wrinkle or split - making them more vulnerable to mould, insect infestation (particularly Coffee Berry Borer), and fermentation on the branch.

When overripe cherries enter the processing stream they can contribute fermented, putrid, or overly sweet off-flavours to the cup. They often develop into sour beans, black beans, or other primary defects during drying.

In strip-picking or mechanical harvesting - where all fruit is removed at once - overripe cherries are an inevitable component. In selective hand-picking, experienced pickers avoid them. But in regions where labour costs or time pressure require faster harvesting methods, some overripe cherry invariably enters the crop. Float separation at intake is one of the most effective ways to remove them before they cause further problems downstream.